These changes are primarly made to make mcl_autogroup more efficient.
Previously enchanted tools required storing around 21 kB of metadata due
to the way the previous version of the mod was implemented. This caused
a lot of lag and a huge amount of network traffic. With the changes
enchanted tools won't require more than 1 kB of metadata.
The mod is also rewritten to use an API to register digging groups and
compute the groupcaps for tools. This will make it easier for modders
to register custom digging groups.
The mod is now split up into two parts. One part called "mcl_autogroup"
to implement the API for registering custom digging groups, and the
other part called "_mcl_autogroup" which contains most of the code which
has to be loaded after most mods.
This involves MASSIVE hacks around the digging system in Minetest.
Implemented so far: Hardness, nodes in mcl_core, digging for nodes
diggable by pickaxe, shovel, axe.
Not implemented: Nodes diggable by hand alone (except insta-dig),
shears and sword.
